. Elements of geology : a text-book for colleges and for the general reader. Geology. Fig. 444.—Homocercal Tail-fin : A, form; B, structure. Fig. 445.—Heterocercal or Vertebrated Tail-fin: A, form; B, structure. tail-fins. Therefore, all Devonian fishes, without exception, had verte- brated tail-fins—sometimes asymmetric (Figs 431,434), and sometimes symmetric (Figs. 432,433). 5. In all Teleosts, and in nearly all living fishes, the paired fins (corre- sponding to limbs) are simply fins. The bones of the limbs are buried in the body. But there is one very characteristic Devoni- an family (Cros
. Elements of geology : a text-book for colleges and for the general reader. Geology. Fig. 444.—Homocercal Tail-fin : A, form; B, structure. Fig. 445.—Heterocercal or Vertebrated Tail-fin: A, form; B, structure. tail-fins. Therefore, all Devonian fishes, without exception, had verte- brated tail-fins—sometimes asymmetric (Figs 431,434), and sometimes symmetric (Figs. 432,433). 5. In all Teleosts, and in nearly all living fishes, the paired fins (corre- sponding to limbs) are simply fins. The bones of the limbs are buried in the body. But there is one very characteristic Devoni- an family (Crossopterygi- ans) in which the limb is a lobe of the body running through the fin. The relation between the two styles of paired fins is similar to that of the two styles of tail-. Fig. 446. -Vertebrated bnt Symmetrical Fin: A, form; B, Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original LeConte, Joseph, 1823-1901. New York : D. Appleton and Co.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectgeology, bookyear1892
